This invention relates to a magnetic recording medium, and more specifically to a magnetic recording tape, such as video tape.
Generally, magnetic recording systems, which depend on the sliding contact of a magnetic medium with a magnetic head or heads for recording or playback, can have various troubles along the contact surfaces. Especially with the systems, such as video recorders, wherein very small magnetic heads scan the moving tape faces at high speeds, there is a danger of the magnetic heads seriously damaging the tapes.
For example, tape surfaces which do not have adequate strength tend to be scraped as they run past the heads. When this happens, the resulting dust of coating will deposit in head gaps, eventually making the recording and playback impossible (due to head clogging). Other possible phenomena include deterioration of the still picture quality (i.e., shortened still time) and a decrease in the signal output with repeated usage.
Many different methods have been proposed to settle the foregoing problems. Of those, reinforcement of the magnetic coating film by the addition of a nonmagnetic powder having a Mohs hardness of over 6 has proved relatively effective. On the other hand, the film reinforced with such a hard substance affects the magnetic heads seriously, with accelerated head abrasion.